138562639 has 4 divisors (see below), whose sum is σ = 138597856. Its totient is φ = 138527424.

The previous prime is 138562579. The next prime is 138562643. The reversal of 138562639 is 936265831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936265831 = 19 ⋅49277149.

It is a cyclic number.

It is not a de Polignac number, because 138562639 - 2¹³ = 138554447 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138562595 and 138562604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138562679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10839 + ... + 19864.

It is an arithmetic number, because the mean of its divisors is an integer number (34649464).

Almost surely, 2^138562639 is an apocalyptic number.

138562639 is a deficient number, since it is larger than the sum of its proper divisors (35217).

138562639 is an equidigital number, since it uses as much as digits as its factorization.

138562639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35216.

The product of its digits is 233280, while the sum is 43.

The square root of 138562639 is about 11771.2632712042. The cubic root of 138562639 is about 517.4662727053.

The spelling of 138562639 in words is "one hundred thirty-eight million, five hundred sixty-two thousand, six hundred thirty-nine".